Stabilizer bar



July 8, 1969 J. R. KENNEDY 3,454,308

STABILIZER BAR Filed Jan. 19, 1968 -ENTOR. JOHN R. KENN Y ATTORNEYS United States Patent 3,454,308 STABILIZER BAR John R. Kennedy, 1751 W. Klamath Drive, Tucson, Ariz. 85704 Filed Jan. 19, 1968, Ser. No. 699,241 Int. Cl. F16c 1/26, 17/00, 29/00 US. Cl. 308-4 4 Claims ABSTRACT OF THE DISCLOSURE The present invention pertains to stabilizers, and more particularly, to stabilizer bars of the type utilized in drilling.

When drilling in rock in such instances as the preparation of a hole for blasting, and in other instances wherein the shaft of the drill is likely to encounter abrasive material, it is known in the art to utilize stabilizer bars. The stabilizer bars contact the surface of the hole and stabilize the drill bit during its descent. Since the surface of the stabilizer is continuously subjected to abrasive material, frequent removal and replacement is required.

To enhance the life of stabilizer bars, the prior art has attempted to incorporate wear bars in the stabilizer to contact the surface of the hole. Various attempts have been made at utilizing removable wear bars such that when the bars become worn they may readily be removed and replaced; however, the various attempts have failed, primarily because of the manner in which they were attached to the stabilizer. One very frequently utilized approach to the attachment of wear bars on a stabilizer bar is simply to weld the wear bars onto the stabilizer bar; however, a distinct disadvantage is inherent in this scheme since when the wear bars become worn, it is necessary to remove the stabilizer section of the drill and return it to a workshop for removal and subsequent rewelding of new wear bars. This operation inherently requires a substantial delay time which must be remedied by maintaining a substantial number of stabilizer bars with wear bars welded thereto in the field. By making the Wear bars removable in the field, the operation of replacing the wear bars becomes a simple matter without the necessity of transmitting the apparatus to a machine shop. 1

It is therefore an object of the present invention to provide a stabilizer bar having removable wear bars.

It is another object of the present invention to provide a stabilizer bar having removable wear bars incorporating a unique means of attachment.

It is still another object of the present invention to provide a stabilizer bar incorporating removable wear bars that are readily removable and replaceable in the field without the necessity of complicated equipment or without permanently attaching the wear bar to the stabilizer as by welding.

These and other objects of the present invention will become apparent to those skilled in the art as the description thereof proceeds.

Briefly, in accordance with the embodiment chosen for illustration, a stabilizer bar is provided with a plurality of slots extending longitudinally of the stabilizer; each slot incorporates straight sides and undercut tapered Patented July 8, 1969 ends. Wear bars having mating straight sides and tapered ends are inserted in the slots provided in the stabilizer and are secured in place by a plurality of locking bars, each positioned between a pair of wear bars. The wear bars are provided with carbide inserts for increasing the life of the wear bar.

The present invention may more readily be described by reference to the accompanying drawings, in which:

FIGURE 1 is a perspective view of a stabilizer bar incorporating the teachings of the present invention.

FIGURE 2 is a cross-sectional view of FIGURE 1 taken along line 2--2.

FIGURE 3 is a cross-sectional view of FIGURE 1 taken along line 33.

FIGURE 4 is a top view, enlarged, of a wear bar of FIGURE 1.

FIGURE 5 is a top view, enlarged, of another wear bar of FIGURE 1.

FIGURE 6 is a top view of a locking bar of FIG- URE 1.

FIGURE 7 is a cross-sectional view of FIGURE 4 taken along line 77.

Referring now to the drawings, a stabilizer bar 10 is shown and, in the embodiment chosen for illustration, comprises a substantially cylindrical hollow member having a fitting-receiving end 11 adapted to receive the shank of a bit. The opposite end 12 of the bar 10 is shaped for securing the stabilizer bar 10 to the shaft of a drilling assembly. The stabilizer bar includes a plurality of diametrically spaced slots 15 having straight sides and undercut or dovetailed ends 16. In the embodiment chosen for illustration, four slots are shown; however, it will be obvious to those skilled in the art that any number of slots may be utilized. Each slot is provided with a plurality of wear bars such as the bars 20 and 21. Each of the bars includes straight untapered sides 26, 27, and 28, 29 respectively. Each of the wear bars is also provided with tapered ends 30 which are tapered at an angle corresponding to the dovetailed or undercut taper 16 of the stabilizer bar 10.

The wear bars such as 20 and 21 may then be placed in one of the slots 15 and positioned with the corresponding tapered ends in abutting relation with the ends of the slot. Since the tapered ends match the dovetailed tapers or undercuts of the slots, the bars are prevented from lifting out of the stabilizer bar 10. To lock the wear bars in position, a plurality of locking bars 33 are provided, each of which includes tapered ends 31 and 32 which are tapered at an angle to correspond with the tapering provided at the ends of the wear bars. After the Wear bears have been placed in position as described above, the locking bar is placed between two of the wear bars and is secured in place through the utilization of any convenient fastening means, such as a machine screw 35. In the embodiment chosen for illustration, the locking bar is shown having a top surface 40 flush with the upper surface of the wear bar; however, in actual practice, the locking bar may actually be slightly lower than the wear bars since the principal function of the locking bar is merely to keep the wear bars from falling out of the stabilizer 10. The sides of the locking bar are straight and are the same width as the wear bars which, in turn, are approximately the same width as the slots provided in the stabilizer. Since the wear bars have straight untapered sides, the forces imparted thereto by the rotation of the stabilizer and the abrading resistance of the walls of the hole will not cause the bars to work loose or to become jammed in the stabilizer. If the dovetailing or tapering of the slots were to be longitudinal, the forces imparted to the wear bars would jam the mating surfaces together, rendering it very diiiicult to remove the wear bar when it becomes worn.

To enhance the resistance to abrasion and to increase the wear resistance of the wear bars, a plurality of inserts 40 are provided and are mounted within the Wear bar and extend slightly from the surface thereof as shown in FIGURE 7. In this manner, the actual abrasion occurring between the stabilizer and the walls of the hole are primarily taken up by the external surfaces of the inserts. Further, in the embodiment chosen for illustration, inserts are provided on the surface 40 of the locking bar 33; this latter provision of inserts on the locking bar is optional and may not be necessary if the locking bar surface 40 is below the outer surfaces of the corresponding wear bars.

In operation, the stabilizer is fitted with wear bars by placing the wear bars in the longitudinal slots provided in the stabilizer. The bars are positioned with their tapered ends in abutting relationship with the transversely undercut or dovetailed slot ends. The bars are thus locked in position by a locking bar which is provided with corresponding tapers at either end thereof in engagement with the adjacent ends of two wear bars, the locking bar secured to the stabilizer by means of a machine screw. More than a single pair of wear bars may be mounted in a single slot; for example, in some instances where extreme abrasive conditions occur, it may be advisable to include a greater bearing surface to more evenly distribute the wear. In such instances, it may be advisable to extend the longitudinal slots in the stabilizer for a greater length and incorporate more than a single pair of wear bars. When the wear bars become worn, it is only necessary to remove the stabilizer and disengage the locking bars by unscrewing the machine screws. The wear bars may readily be removed without difficulty since the forces encountered by the abrasion between the wear bars and the wall of the hole are exerted on straight untapered surfaces and are not directed against any mating tapered surfaces. The bars may simply be replaced as described above and the stabilizer is ready for reuse. It will be apparent to those skilled in the art that many modifications may be made in the system of the present invention without departing from the spirit and scope thereof. Accordingly, it is intended that the present invention be limited only by the scope of the claims appended hereto.

I claim:

1. In a drilling stabilizer including a stabilizer bar having an axis extending longitudinally in the direction of the hole being drilled, the improvement comprising: a plurality of slots in said stabilizer bar extending parallel to said axis, each slot having straight sides and undercut ends, said undercut ends being substantially transverse to said axis; a plurality of wear bars positioned in each of said slots, each of said wear bars having straight sides and tapered ends for mating with the straight sides and undercut ends of said slots; a plurality of locking bars having straight sides and tapered ends secured in said slots between wear bars, the straight sides of said locking bars abutting the straight sides of said slots and the tapered ends of said locking bars mating with the adjacent tapered ends of adjoining Wear bars for maintaining said wear bars in position in said slots; and a plurality of inserts of wear-resistant material mounted in said wear bars and extending therefrom for contacting the walls of the hole being drilled.

2. The combination set forth in claim 1 wherein said slots are diametrically spaced about said stabilizer bar.

3. The combination set forth in claim 1 wherein two wear bars with a locking bar therebetween are positioned in each of said slots.

4. The combination set forth in claim 1 wherein said locking bars are secured to said stabilizer bar by means of machine screws threaded into said stabilizer bar.

References Cited UNITED STATES PATENTS 1,814,271 7/ 1931 Vaughn. 2,247,173 6/ 1941 Huntsinger. 2,288,124 6/ 1942 Creighton. 3,054,647 9/ 1962 Rosenberg. 3,268,274 8/ 1966 Ortloff. 3,306,378 2/1967 Williams 325 FOREIGN PATENTS 763,529 5/1934- France.

MARTIN P. SCHWARDRON, Primary Examiner.

L. L. JOHNSON, Assistant Examiner.

US. Cl. X.R. 

